Synthesis and characterization of new chiral azolinium salts, precursors to N-heterocyclic carbenes, derived from l-proline

摘要

A short and flexible procedure for the preparation of seven chiral azolinium and five functionalized chiral azolinium salts, precursors to N-heterocyclic carbenes, derived from l-proline has been developed. Moderate to good overall yields were obtained. Some NHC dimers and thiones were isolated. X-ray crystal structure determinations of two [Rh-NHC] complexes were also reported.